Speaker
Description
Extracellular self-DNA has emerged as a species-specific regulator of plant growth, yet its effects and physiological responses in aquatic plants remain poorly understood. This study investigated whether extracellular self-DNA preferentially inhibits growth in a two-species duckweed community and whether this response is associated with oxidative stress. Lemna perpusilla and Spirodela polyrhiza were exposed to self-DNA, non-self DNA, and mixed DNA. A dose–response assay using genomic DNA solutions ranging from 0 to 2,000 ng µL⁻¹ identified the most inhibitory treatment. Growth was evaluated using frond number, root number, root length, fresh biomass, and dry biomass. Species specificity was examined by co-cultivating both species and exposing the culture separately to DNA from each species. Physiological responses to self-DNA at 1,000 ng µL⁻¹ were assessed through reactive oxygen species (ROS), superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), and malondialdehyde (MDA). Self-DNA caused stronger inhibition than non-self DNA and mixed DNA. In the two-species community, L. perpusilla DNA reduced L. perpusilla fresh biomass by 76.5% but S. polyrhiza by only 3.2%. Conversely, S. polyrhiza DNA reduced S. polyrhiza fresh biomass by 93.3% but L. perpusilla by only 14.5%, demonstrating reciprocal species-preferential inhibition. Self-DNA also increased ROS accumulation by 39% in L. perpusilla and 54% in S. polyrhiza, accompanied by enhanced SOD, POD, and CAT activities and elevated MDA levels. These findings show that extracellular self-DNA preferentially inhibits its source species within a mixed duckweed community and that this response is associated with oxidative stress, supporting investigation of self-DNA recognition and species-targeted aquatic plant management.
Keywords
autotoxicity; eDNA; Lemna; stress; Spirodela
References
Cartení F, Bonanomi G, Giannino F, Incerti G, Vincenot CE, Chiusano ML, Mazzoleni S. 2016. Self-dna inhibitory effects: Underlying mechanisms and ecological implications. Plant Signal. Behav. 11(4):1–4.doi:10.1080/15592324.2016.1158381.
Mazzoleni S, Cartenì F, Bonanomi G, Senatore M, Termolino P, Giannino F, Incerti G, Rietkerk M, Lanzotti V, Chiusano ML. 2015. Inhibitory effects of extracellular self-DNA: A general biological process? New Phytol. 206(1):127–132.doi:10.1111/nph.13306.
Bog M, Appenroth KJ, Schneider P, Sowjanya Sree K. 2022. Intraspecific Diversity in Aquatic Ecosystems: Comparison between Spirodela polyrhiza and Lemna minor in Natural Populations of Duckweed. Plants. 11(7).doi:10.3390/plants11070968.
